Chlorofluorocarbons (CFCs) are known and widely used in the industry as solvents, blowing agents, heat transfer fluid, aerosol propellants and other uses. But CFCs are also well-known to have ozone depletion potential (ODP) and are regulated by the Montreal Protocol. A suitable replacement material would have negligible or no ODP, as well as an acceptable global warming potential (GWP).
1-Bromo-3,3,3-trifluoropropene, 2-bromo-3,3,3-trifluoropropene and 1,2-dibromo-3,3,3-trifluoropropene each have desirable ODP and GWP, and could potentially used as high efficiency fire extinguisher agents. For example, CN 102319498 A describes a dry powder fire extinguisher having 2-5 wt % of 2-bromo-3,3,3-trifluoropropene, the composition having high moisture-proof performance, high reburning resistance, and high fire extinguishing efficiency. Similarly, Zhang et al found a bromotrifluoropropene/zeolite mixture to be a highly efficient fire extinguisher (Zhongguo Anquan Kexue Xuebao 2011, 21(5), 53; Process Safety and Environmental Protection 2007, 85(B2), 147; Huozai Kexue (2010), 19(2), 60-67). 1-Bromo-3,3,3-trifluoropropene with an inert gas have many of the desirable properties of HALON 1301 fire extinguishing agents. The results show that the composites loaded with bromotrifluoropropene exhibited much better performance than that of common dry powders in putting out gasoline fires, requiring less powder, and having shorter fire extinguishing time.
One existing production process for 1-Bromo-3,3,3-trifluoropropene requires the reaction of 3,3,3-trifluoropropene with bromine, followed by dehydrobromination, to give the target compound. This process is very expensive, and not suitable for large quantity production.
Other production processes for bromotrifluoropropenes have been investigated. J. Chem. Soc. 1951, 2495 describes bromination of CF3CH═CH2 followed by alkaline treatment to give 2-bromo-3,3,3-trifluoropropene. J. Chem. Soc. 1952, 3490 describes hydrogen bromide (HBr) reaction with 3,3,3-trifluoropropyne at 0° C. or with AlBr3 at −25° C. to give 1-bromo-3,3,3-trifluoropropene at high yield. Also, HBr reacted with 3,3,3-trifluoropropyne in a sealed cylinder with or without AlBr3 yields 1-bromo-3,3,3-trifluoropropene in high yield (83-91% yield) when reacted at low temperatures (J. Chem. Soc. 1952, 3490; J. Am. Chem. Soc. 1952, 650). 2-Bromo-3,3,3-trifluoropropene is an important intermediate for pharmaceutical and agrochemicals and was often used as the precursor of 3,3,3-trifluoroacetylenic anion and could dehydrobrominated with LDA or BuLi at 0° C. (J. Org. Chem. 2009, 7559-61; J. Flu. Chem. 1996, 80, 145-7). Finally, Mori et al used 1,2-dibromo-3,3,3-trifluoropropene reacting with 20% aqueous NaOH to produce 2-bromo-3,3,3-trifluoropropene in 98% yield (JP 2001322955).